Fuse too big on fridge

[John-SJW]

a 13amp plug top are what we class as fixed current equipment and therefore do not need overload protection

Assuming there is no fault of course. In a fault condition it may draw more current than it is designed to, with a fire/electrocution risk. That is where correctly sized overload protection comes in - to nip the danger in the bud.

I have seen enough innards of burnt out appliances that would have benefited in safety aspects having a correctly sized fuse in the plug, with 13A being far too high.

Your point about manufacturers increasing fire/electrocution risk because of profit is relevant.

 

[John-SJW]

You have a very strange attitude. You remind me of the antivax type people with the way you argue and refuse to listen to reason.

There will always be cases of things that are electrically sound, but don't necessarily comply with BS7671. The regs cannot cover every eventuality. You are free to do things that don't comply, as long as you justify your deviations.

Did you understand what I wrote? Looks like you never.
I told him not to look at regs, then electrically assess, where an appliance with a current draw of 0.3A on a dedicated radial, with 1.00mm cable with 10A mcb. I asked him to tell me where it not safe. He continually spouted the regs, unable to assess it, and still has not.

The scenario I gave is 100% safe. The regs say minimum of 1.5mm for power, which is good practice. There is a reason why they set that. So as the hard of thinking do not cause fires.

Electricians are trained to follow procedures and regs - think inside the box.
Graduate engineers are educated to think - promoting outside the box thinking. That is why the British are very inventive. Training and education are different. The British system does differentiate between the two.

 

[DPG]

Did you understand what I wrote? Looks like you never.
I told him not to look at regs, then electrically assess, where an appliance with a current draw of 0.3A on a dedicated radial, with 1.00mm cable with 10A mcb. I asked him to tell me where it not safe. He continually spouted the regs, unable to assess it, and still has not.

The scenario I gave is 100% safe. The regs say minimum of 1.5mm for power, which is good practice. There is a reason why they set that. So as the hard of thinking do not cause fires.

Electricians are trained to follow procedures and regs - think inside the box.
Graduate engineers are educated to think - promoting outside the box thinking. That is why the British are very inventive. Training and education are different. The British system does differentiate between the two.

Please listen to people.

He isn't saying it is not safe. He is saying that it doesn't comply with the regs.

And as I say, there are many circumstances which may be safe, but which do not comply with the regs. The regs cannot cover every eventuality.

And give it a rest with the bold text - it's very patronising and completely unnecessary.

 

[John-SJW]

Please listen to people.

He isn't saying it is not safe. He is saying that it doesn't comply with the regs.

And as I say, there are many circumstances which may be safe, but which do not comply with the regs. The regs cannot cover every eventuality.

And give it a rest with the bold text - it's very patronising and completely unnecessary.

I know that.

He wrote: "You also talked about using an incorrect cable size."
The cable size was not incorrect, it was perfectly suitable and safe. Not conforming to a reg is another matter. He could not figure out the difference.

I did listen, with a lot of narrow minded nonsense coming from some. They should do the listening, not me. Darkwood came out with one of the few sensible replies.

 

[i=p/u]

Say sorry John

 

[westward10]

I know that.

He wrote: "You also talked about using an incorrect cable size."
The cable size was not incorrect, it was perfectly suitable and safe. Not conforming to a reg is another matter. He could not figure out the difference.

I did listen, with a lot of narrow minded nonsense coming from some. They should do the listening, not me. Darkwood came out with one of the few sensible replies.

I will close this if you continue with your current attitude.

 

[Spoon]

A reg quoter again. Lokks like someone who has been trained. I told you not to look at regs, then assess, then tell me where it is not electrically sound and not safe. I am still waiting.

You really don't like being wrong. ???
How can I tell you that your idea of using 1.0mm cable is not 'electrically correct' if you don't want me to point you to something, like the regs... You make no sense what so ever.
I'm not sure what you are waiting for, you are wrong, deal with it. ?
You are doing great at getting your post count up quickly though, I will give you that..

 

[John-SJW]

Holy Moses.

 

[nicebutdim]

Electricians are trained to follow procedures and regs - think inside the box.
Graduate engineers are educated to think - promoting outside the box thinking. That is why the British are very inventive. Training and education are different. The British system does differentiate between the two.

Perhaps this discussion would be better held on a 'Graduate Engineer's forum', although I suspect more than one graduate engineer has participated in this thread.

Your opening post states "If having a{sic} mcb or RCBO at the CU for just the fridge, a 1.00mm cable can be run on a radial for it." This may be technically correct (or it may not, depending on factors that haven't been disclosed), but from a regulatory perspective it would not be permissible.

Given that this is an 'Electrician's' forum, it might be an idea to make clear when you wish to set regulations to one side and discuss hypothetical situations. Otherwise such arguments can appear to be pointless polemic pedantry, to the casual observer, or may be taken at face value by a hapless DIYer who happen to stumble across this thread in their quest for information.

 

[Lucien Nunes]

Suppose the OP had written the post as follows:

'Possible justification for deviating from MI's regarding fuse rating'
A certain fridge is supplied with a 13A fuse in the plug and the MI's state that this size is to be used. However, the consumption is low, a fraction of an amp when running, and I suspect even the stall current would not blow or even stress a fuse of much lower rating, maybe even as low as 3A. Therefore, although the unit presumably conforms to the applicable standards as-is with a 13A fuse and would be regarded as safe, deviation from the MI's to use a smaller fuse might yet add marginally to its safety in the event of certain types of fault. For example, reducing the risk of fire in the event of motor failure and gross overcurrent that the internal thermal protection does not successfully disconnect, or reducing the energy dissipated at a short-circuit fault. Given the disparity between the actual current and the implied need for a 13A fuse, and the fact that any reliability disadvantage from using a smaller fuse is one of lost functionality rather than reduced safety, I contend that it is a good example of where the application of technical knowledge can enhance safety compared to slavishly following MI's.

On the same subject although not enhancing safety, subject to Zs and VD, the appliance could manifestly run from its own dedicated circuit wired in 1.0mm² on say a 10A MCB. Yet BS7671 requires the cable to be a minimum of 1.5mm² on account of it being a 'power' circuit, despite carrying lower load than many lighting circuits.


I think more of us might have agreed.

Of course, the whole thing rests on the stall current, which means one of use has to hook an ammeter in series with a fridge and twiddle the thermostat while it's running to stall the compressor.

 

[DPG]

And that is where good knowledge and a decent attitude come together to form a decent post.

 

[i=p/u]

Magnitude and time is all that matters here
It trips before it burns like chicken.

 

[DPG]

Magnitude and time is all that matters here
It trips before it burns like chicken.

Glad it's not just who's been drinking.

White rat anyone?

 

[Lucien Nunes]

Ghost Ship for me. Not too many though, early start tomoz. 3 should be safe, 13 would be too many.

 

[i=p/u]

And unlucky

 

[DPG]

Ghost Ship for me. Not too many though, early start tomoz. 3 should be safe, 13 would be too many.

Adnams - Norfolk/Suffolk?

Just having a Theakston's Pale. Cheers and all the best!

 

[John-SJW]

This may be technically correct

Not may, it is. The statement by me was to point out how low the current draw was on the fridge.

 

[nicebutdim]

Not may, it is. The statement by me was to point out how low the current draw was on the fridge.

Without full details of the circuit in question, it was impossible to determine whether or not your point was technically correct.

Was that 1mm circuit 30' or 30 miles in length? Sorry, but your original comment provided insufficient data to make such a determination. That's how this works, right?

 

[John-SJW]

Without full details of the circuit in question, it was impossible to determine whether or not your point was technically correct.

It was technically correct, just accept it.

 

[nicebutdim]

It was technically correct, just accept it.

Based on the information you originally provided, it may have been technically correct or it may not have been.

One can not be expected to assume unquoted variables in any hypothetical discussion.